1. Field of the Invention
The present invention relates to disk drives and drives to access storage media. More particularly, the present invention relates to disk drive write operations using a write stack operation within the disk drive.
2. Discussion of the Related Art
The write performance of a disk drive may be inefficient where single threaded write operations are being performed. Within known disk drive systems, write operations may incur a command completion time that is proportional to the rotational speed of the disk. For example, a 10,000 rotations per minute (“RPM”) drive may take 6 milliseconds minimum to complete a write command. Existing disk drives may attempt to use memory caches to compensate for the write latencies. The memory caches may be on the drive or the array controller.
Memory caches may be effective in reducing write latencies, but they are volatile unless backed up by a battery. Batteries, however, introduce maintenance and disposal issues. Moreover, memory caches may be limited to short term storage during a power outage. Another attempt to compensate for write latencies is to coalesce, or combine, multiple writes to improve response time. This approach may minimize write latency, but not as significantly as a memory cache. Thus, known disk drive systems may suffer from write latencies, or, in the case of memory caches, data loss in the event of power loss. These problems reduce efficiency of the disk drive systems.